SYRINGE AND SYRINGE BODY

Description

Field of invention

[0001] The invention relates to a syringe prefilled with a medical liquid, comprising a syringe body with a Luer-Lock connection, and a method for manufacturing the syringe body. Background of the invention

[0002] Prefilled syringes, also known as disposable syringes, may consist of a plastic syringe body. To dispense the contained medical fluid, the syringe body has a nozzle at its end. The nozzle serves, for example, to connect a needle or tubing from an administration set. Syringes with a male Luer-lock connection are particularly common. In this type of syringe, the standardized conical nozzle is surrounded by a sleeve with an internal thread.

[0003] Especially with pre-filled syringes, a suitable plastic material should meet various requirements.

[0004] The plastic material should be suitable for as many different medical fluids as possible. In particular, it should largely prevent the diffusion of components of the medical fluid into the material and also the leaching of material components by the medical fluid, even during prolonged storage. Furthermore, a suitable plastic material should also be autoclavable.

[0005] Cycloolefin copolymers have proven to be particularly suitable materials. Firstly, they are well-suited for injection molding. Secondly, they are characterized by high stiffness and hardness combined with relatively low density. Furthermore, these materials are amorphous and highly transparent. They also exhibit low water absorption and low water vapor permeability.

[0006] These plastics, however, can be relatively brittle. Cycloolefin copolymers, for example, have a relatively low elongation at break compared to polypropylene or polyethylene. This can lead to damage to the Luer-lock thread of the syringe if the connection of an infusion set is overtightened. Due to the material's brittleness, it cannot deform significantly, so such damage can occur quite abruptly. As a result, the user receives almost no tactile feedback that the connection has been overtightened.

[0007] To reduce this problem, the German patent application DE 10 2017 112 823 A1 provides for the reinforcement of the threaded sleeve by means of ribs. This improves the mechanical stability of the threaded connection.

[0008] The German patent application EP 3 342 441 A1 proposes that the threaded connection be made of a different material than the syringe body. Specifically, it proposes that the connection piece be injection-molded from a softer material onto the front of the syringe body. Object of the invention

[0009] In contrast, the invention is based on the objective of at least reducing the aforementioned problems of the prior art.

[0010] In particular, it is an object of the invention to provide a plastic syringe pre-filled with a medical liquid, comprising an inner wall made of a material with high chemical resistance and good barrier properties, and which is simultaneously provided with a very stable plastic threaded connection. Summary of the invention

[0011] The object of the invention is solved by a syringe body according to claim 1 and a syringe with this syringe body.

[0012] Preferred embodiments and further developments of the invention can be found in the subject matter of the dependent claims, the description and the drawings.

[0013] The invention relates to a syringe body with a nozzle and a threaded connection, wherein the syringe body comprises an inner part forming an inner wall of the syringe body and comprising a cycloolefin, in particular a cycloolefin copolymer or a cycloolefin polymer, as a first material, and wherein the threaded connection is formed as part of an outer part made of a plastic, which comprises a material other than the cycloolefin as a second material, wherein the outer part extends at least partially around the side wall of the syringe body.

[0014] The invention is therefore based on the basic idea that the syringe body is formed from an inner part and an outer part, wherein the inner part and outer part are made of different materials.

[0015] The invention provides in particular that at least the inner wall, preferably the entire inner wall of the syringe body, is formed from a cycloolefin.

[0016] For the purposes of this invention, cycloolefin means all cycloolefin copolymers obtained by catalyzed copolymerization of cycloolefins.

[0017] For the purposes of the invention, cycloolefins are also understood to include materials obtained by ring-opening salt metathesis. These are more precisely referred to as cycloolefin polymers rather than cycloolefin copolymers.

[0018] The first material preferably consists of at least 50% by weight, and particularly preferably at least 90% by weight, of a cycloolefin.

[0019] Such materials are amorphous, transparent, and interact to a significantly lesser extent with the filled medical fluid, especially an aqueous medical fluid, than other plastics.

[0020] In particular, these may be so-called crystal-clear polymers.

[0021] The outer part, which includes the threaded connection, can, however, be made of a different plastic, in particular a plastic that is mechanically more stable.

[0022] Because the outer part extends around the side wall of the syringe body, no torque is transmitted to the inner part via the threaded connection when a corresponding connection is screwed in.

[0023] The outer part serves as a handle to hold the tip when screwing a connector into the threaded connection.

[0024] The user therefore holds the syringe, particularly by the side wall of the outer part, which also includes the threaded connection. This prevents any torque from being transferred to the inner part.

[0025] The inner and outer parts are therefore less likely to come loose.

[0026] The inner part can be overmolded with the outer part.

[0027] Another embodiment also provides for a positive locking connection, e.g. by snapping.

[0028] The inner and outer parts can also be welded or glued together.

[0029] In one embodiment, the inner and outer parts are inserted into one another. Frictional forces between the walls are sufficient to hold the inner and outer parts together.

[0030] Preferably, the outer part extends around the entire side wall of the inner part.

[0031] The outer part may have cutouts, especially if it is opaque.

[0032] Preferably, the outer part is transparent.

[0033] In one embodiment of the invention, a proximal handle of the syringe or syringe body is part of the outer part. In particular, only the outer part comprises a proximal handle projecting radially outwards.

[0034] This makes it easy to provide a syringe where the handle is also made of the mechanically more robust material.

[0035] In one embodiment of the invention, the wall thickness of the inner part is 0.3 to 3 times, preferably 0.5 to 1.5 times, the wall thickness of the adjacent wall of the outer part. This applies particularly to the side wall. In particular, the inner and outer parts have approximately the same wall thickness.

[0036] The inner part therefore has a relatively high wall thickness and thus provides a good barrier effect, especially for water vapor and / or oxygen.

[0037] The overall wall thickness, especially in the area of ​​the side wall, can be, for example, . between 0.3 mm and 5 mm, preferably between 0.6 mm and 2.5 mm.

[0038] In one embodiment of the invention, the outer part also extends around the nozzle of the inner part.

[0039] When the connector is plugged in, the female connector slides over the outer part. This prevents axial forces acting on the inner part that could detach it from the outer part.

[0040] When filled as a pre-filled syringe, a nozzle closure, for example a seal, preferably engages the nozzle. This prevents the material of the outer part from coming into contact with the liquid inside the syringe during storage.

[0041] In a further development of the invention, the inner part comprises a structuring on the front of its end wall, into which a complementary structuring on the back of the outer part engages.

[0042] The syringe body comprises at least a two-layered area, within which the first and second materials have an interlocking structure.

[0043] Due to the inner part and the outer part, the syringe body has a two-layer structure, at least in some areas.

[0044] This embodiment of the invention is provided both for a syringe in which the inner part and outer part are positively connected to each other, and for a syringe with the outer part being materially connected to the inner part.

[0045] A structuring refers to a regular or irregular height profile of the inner part with raised or recessed areas. The second material of the outer part, which is injection-molded, for example, fits into these recesses.

[0046] The surfaces of the first and second materials adjacent to each other at a contact surface or interface within the two-layer area each comprise a surface relief with a profile structure that is at least partially filled by the other material.

[0047] It has been found that this significantly reduces the tendency of the two layers to separate, especially during autoclaving and / or under mechanical stress.

[0048] Stresses, such as those caused by different coefficients of thermal expansion of the materials, are not only distributed essentially radially along a smooth surface due to the peaks and valleys, but are also partially redirected in an axial direction.

[0049] The linear coefficient of thermal expansion for cycloolefin copolymers (under standard conditions) is typically below 60 x 10⁻⁶ < x K⁻¹ < . Polypropylenes, on the other hand, have a higher coefficient of linear thermal expansion, in particular above 150 x 10⁻⁶ < x K⁻¹ < .

[0050] Despite the strength and a certain brittleness of the cycloolefin copolymer, the bond does not break down, especially during an autoclaving process, due to the different thermal expansion of the two materials.

[0051] Furthermore, the structuring increases the surface area of ​​the interface between the first and second materials. Preferably, this interface is at least 20% larger compared to an unstructured design.

[0052] Finally, the structuring can provide a positive fit between the first and second materials, especially against torque between the components when a connector is connected to the threaded connection.

[0053] This allows for a very simple way to provide an improved mechanical connection.

[0054] Furthermore, the structuring increases the surface area of ​​an interface or contact surface between the first and second materials. Preferably, this interface or contact surface is at least 20% larger compared to an unstructured design.

[0055] Finally, the structuring can provide a positive fit between the first and second materials, especially against torque between the inner and outer parts.

[0056] This allows for a very simple way to provide an improved mechanical connection.

[0057] Furthermore, the production of such a syringe does not involve significantly increased effort. Only an injection mold is required for the production of the inner part, which includes a negative profile in the shape of the inner part's profile.

[0058] Insofar as structuring is mentioned below, this can refer to the structuring of the inner part as well as the structuring of the outer part, especially on its end walls.

[0059] These structures preferably have a complementary design.

[0060] The surveys can be designed as regular and / or irregular surveys. Similarly, the indentations can be designed as regular and / or irregular indentations.

[0061] In one embodiment of the invention, the protrusions and / or depressions are formed as concentric rings. With such a profile, the protrusions and depressions extend radially from the inside to the outside. This results in a uniform deflection of stresses in the axial direction throughout.

[0062] The raised or recessed areas can, in particular, have a substantially triangular cross-section. In this embodiment, the profiling is designed as a sawtooth profile. However, other structures are also possible, such as a wave shape, especially a sinusoidal shape, interlocking knobs, etc.

[0063] In one embodiment of the invention, the structuring elements of the first material are conically shaped. These structuring elements, e.g., the ridges or bumps, taper upwards. This facilitates the application of the structuring elements to the second layer by injection molding the second material. In particular, it reduces the tendency for bubble formation in the area adjacent to the structuring elements.

[0064] In one embodiment of the invention, the structuring on the front of the end wall of the inner part comprises at least one ridge and / or a groove extending from the nozzle, at least partially, towards the side wall. This effectively provides an anti-rotation device. The structuring elements can also be designed as knobs and / or wedges.

[0065] In one embodiment, the structuring of the end wall of the inner part can have at least one, preferably a plurality, of radially extending ribs and / or grooves. The ribs or grooves can have any cross-section. Preferably, however, they are designed with a sawtooth profile.

[0066] Due to the radial alignment, the bridge and groove each form a positive fit, which acts like an anti-rotation device.

[0067] In particular, the top view of the structure can exhibit a fan-like and / or star-like design. For example, the rods of a fan are formed by radially extending webs, and the covering is formed by the ring-shaped profile extending between the webs. The fan extends around the threaded connection and covers 360° of the end face.

[0068] The structuring can have between 3 and 16, preferably between 6 and 10 radially extending ribs and / or grooves distributed around the circumference.

[0069] The positive locking mechanism provided by the structuring serves in particular to improve the strength of the connection under torque load, such as when the connection is screwed in tightly.

[0070] In a further development of the invention, the outer part made of the second material is thickened around the threaded connection compared to a radially adjacent area of ​​the outer part or the end wall of the outer part made of the second material.

[0071] In the transition area between the threaded connection and the end wall, the material of the second layer is reinforced by a thickening, such as a bead or an internal chamfer. This reduces the risk of the threaded connection breaking off if it is overtightened.

[0072] Furthermore, especially when using a soft second material, the deformation of the material in the area of ​​the end wall is reduced during tightening, which in turn reduces the tendency of the material-bonded connection to loosen in this area.

[0073] The second material is preferably a plastic, in particular a transparent plastic that can be processed using injection molding.

[0074] Preferably, the second material has a higher impact strength than the first material. In particular, the second material has an impact strength that is at least 20%, preferably at least 50%, higher than that of the first material.

[0075] Impact toughness is a material property that defines a material's susceptibility to cracking under dynamic loading. It is determined in the Charpy impact test. The dynamic bending caused by the sudden impact results in fracture, often without the yielding of the material observed under slow loading.

[0076] In accordance with the invention, all material properties, in particular the impact strength and the following material properties such as modulus of elasticity and hardness, are determined under standard conditions, i.e. 20 °C and 50% relative humidity.

[0077] The impact strength according to the invention is determined according to DIN ISO 179-1 (11 / 2010).

[0078] In this test, a standardized test specimen with a notch is subjected to an impact pendulum. The pendulum, with a defined kinetic energy, notches or penetrates the specimen. The notch is then measured, or, in the case of penetration, the height to which the pendulum rebounds is recorded. The impact energy dissipated can be calculated from the weight of the pendulum and the difference between its initial and final positions. This impact energy is the product of the specimen's cross-sectional area and its impact strength.

[0079] Cycloolefins generally have an impact strength of less than 3 kJ / m². In contrast, the second material should have a higher impact strength, in particular above 3.5 kJ / m², preferably above 5 kJ / m².

[0080] Polypropylene can be used as a second material.

[0081] Semi-crystalline polypropylene, in particular, has good mechanical properties and is also transparent.

[0082] The second material can be softer than the first material.

[0083] In particular, the second material may have a Shore D hardness (according to DIN ISO 7619-1 (2 / 2012)) of less than 75, especially less than 70.

[0084] In contrast, in one embodiment of the invention, the cycloolefin has a Shore D hardness of over 80.

[0085] In one embodiment of the invention, the second material has a smaller modulus of elasticity than the first material.

[0086] In particular, the Young's modulus of the second material (according to DIN ISO 527-1 (2 / 2019)) is between 1000 and 1800 MPa. The Young's modulus of the cycloolefin can be between 1800 and 2200 MPa.

[0087] An important characteristic for the second material is, in particular, its elongation at break.

[0088] According to one embodiment of the invention, the second material has an elongation at break that is at least 1.5 times, preferably at least 5 times, and particularly preferably at least 10 times higher than the first material.

[0089] The elongation at break is also determined according to DIN ISO 527-1. It is given as a percentage.

[0090] The cycloolefin used may, for example, have an elongation at break of less than 5%, whereas, for example, a polypropylene used may have an elongation at break of 100% or more.

[0091] To cause a threaded connection to break, the material must be deformed beyond its upper yield strength. A trained user will typically notice the subsequent plastic deformation of a material with high elongation at break, thus recognizing that the connection's load-bearing capacity has already been exceeded.

[0092] In one embodiment of the invention, the structuring on the front face of the end wall of the inner part is limited, in particular, by a radially circumferential rib. The structuring terminates within the end wall of the inner part.

[0093] The bridge can be formed in particular by a front section of the side wall of the inner part.

[0094] According to one embodiment, the structuring of the first and / or the second material has a maximum structural depth of over 0.1 mm, preferably over 0.25 mm, and / or of less than 1 mm, preferably less than 0.5 mm. The maximum structural depth is understood to be the height difference between the crest of a protrusion and the bottom of a depression. The structuring is therefore of the macro scale, thereby effectively achieving the force redirection described above.

[0095] The distance between elevations or depressions, the so-called structure width, is, in one embodiment of the invention, more than 0.2 mm, preferably more than 0.5 mm, and / or less than 3 mm, preferably less than 1.5 mm.

[0096] Furthermore, according to one embodiment of the invention, the ratio of maximum structural depth to structural width can be greater than 0.1, preferably greater than 0.25, and / or less than 1, preferably less than 0.5.

[0097] In one embodiment of the invention, the wall thickness of the layer made of the first material in the area of ​​the end wall is 0.3 to 3 times, preferably 0.5 to 1.5 times, the wall thickness of the layer made of the second material. The total wall thickness, particularly in the area of ​​the end wall which is formed in at least sections as two layers, can be, for example, between 0.3 mm and 5 mm, preferably between 0.6 mm and 2.5 mm.

[0098] The invention also encompasses a syringe comprising a syringe body according to one of the embodiments described above, wherein the syringe has a stopper with which the nozzle is closed, a piston, and, in particular, a piston rod for dispensing the medical fluid via the nozzle. The piston rod can be pre-assembled on the piston or provided separately.

[0099] The syringe according to the invention is preferably filled with a medical liquid, in particular with one containing a drug.

[0100] In this exemplary embodiment, the syringe is a pre-filled syringe.

[0101] In particular, the syringe is contained in a preferably oxygen-impermeable outer packaging, for example, a tear-open foil package. The syringe, preferably the packaged syringe, is in particular autoclaved.

[0102] In particular, the syringe is contained in a preferably oxygen-impermeable outer packaging, for example a tearable foil packaging.

[0103] The syringe was autoclaved in this outer packaging, for example at a temperature above 110°C, preferably above 120°C, and is thus completely sterile.

[0104] According to one embodiment, the medicinal fluid is an oxygen-sensitive drug fluid, for example, a drug emulsion. According to one embodiment, the drug fluid is or comprises propofol, in particular a propofol emulsion. Propofol is described by the chemical name 2,6-diisopropylphenol (IUAPC).

[0105] The syringe body can be manufactured, for example, using an injection molding process.

[0106] First, an inner part made of a cycloolefin is injected as the first material.

[0107] For this purpose, an injection mold is used which includes the negative of a structuring of the end wall of the inner part, so that an inner part with a structured end wall is created.

[0108] Subsequently, an outer part with a threaded connection made of a second material is injection-molded around the inner part.

[0109] In the area of ​​the structured end wall of the syringe body, the outer part automatically forms a complementary structure which, as explained above, significantly improves the mechanical connection between the two materials. Brief description of the drawings

[0110] The subject matter of the invention will be described below using exemplary embodiments according to Figs. 1 to 10 will be explained in more detail. Fig. 1 is a side view of an embodiment of a syringe according to the invention. Fig. 2 is an axial sectional view along line AA of the Fig. 1 . Fig. 3This is an axial sectional view of the syringe body. Fig. 4 shows an alternative embodiment of a syringe body. Fig. 5 is a detailed view of area D of the Fig. 4 Fig. 6 This is a perspective view of the syringe head. Fig. 7 This is a perspective view of the head of the inner part. Fig. 8 This is a top view of the end wall of the syringe body. Fig. 9 is a sectional view along line B according to Fig. 8 . Fig. 10 is a sectional view along line C according to Fig. 8 . Detailed description of the drawings

[0111] Fig. 1 shows in a side view an embodiment of a syringe according to the invention 1.

[0112] The syringe 1 comprises a syringe body 2 with a threaded connection 5 and a proximal handle 9.

[0113] As shown in the axial sectional view according to Fig. 2As shown, the syringe body 2 provides an internal volume 3 that is pre-filled with a medical fluid. A gas volume within the internal volume 3 compensates for pressure fluctuations and, in particular, prevents the syringe body 2 from deforming under pressure changes.

[0114] The nozzle 4 is closed with a seal 9, which preferably engages in the nozzle 4, so that the outer wall of the nozzle 4 does not come into contact with the medical fluid, at least when closed.

[0115] Nozzle 4 and threaded connection 5 form the connection of the syringe 1, which is designed in particular as a male Luer-Lock connection.

[0116] The medical fluid can be dispensed through the nozzle 4 via the piston rod 8, which is connected to the piston 6.

[0117] Fig. 3 shows only the syringe body 2 in an axial sectional view.

[0118] The syringe body 2 is designed in two parts and comprises an inner part 100 made of cycloolefin and an outer part 200, which is made of a mechanically more stable material than the inner part 100, in particular polypropylene.

[0119] The 5 / 201 threaded connection is provided solely by the outer part 200.

[0120] The invention is intended for syringes with virtually any volume, in particular from 1 ml to 100 ml.

[0121] In the embodiment according to Fig. 3 A relatively large syringe, in particular with an internal volume of approximately 50 ml, is shown.

[0122] Fig. 4 is an axial sectional view of an alternative embodiment of a syringe body 2.

[0123] This embodiment involves a relatively small syringe, in particular with an internal volume 3 of approximately 5 ml. However, the basic structure of the syringe body 2 remains unchanged.

[0124] The dimensions of the connection, consisting of nozzle 4 and threaded connection 5, do not differ.

[0125] Therefore, the threaded connection 5 has a significantly larger diameter in relation to the maximum diameter of the syringe body 2.

[0126] Fig. 5 is a detailed representation of area D of the Fig. 3 , i.e., the proximal end of the syringe body 2.

[0127] The side wall of the syringe body 2 is formed in two layers and consists of the side wall 102 of the inner part and the adjacent side wall 202 of the outer part 200.

[0128] In contrast, the handle 7 / 204 consists, at least in sections, only of the material of the outer part 200.

[0129] In this embodiment, the inner part 100 has a proximal collar 107 which projects into the handle 204 and improves, for example, the axial positioning in an embodiment in which the inner part 100 and the outer part 200 are pushed into one another, or which makes the handle 6 stiffer in an embodiment in which the inner part 100 is overmolded with the outer part 200.

[0130] Fig. 6 Figure 1 shows in a perspective view the head of a syringe 1 according to an embodiment of the invention.

[0131] The syringe body 2 is formed, as above, from inner part 100 and outer part 200, so that in this view only the inner wall of the nozzle 4 of the inner part 100 can be seen.

[0132] The threaded connection 5 / 201 with an internal thread extends around the nozzle 4 / 210, which is designed in two layers.

[0133] Fig. 7The corresponding perspective view shows only the inner part 100 made of cycloolefin.

[0134] The end wall 103 of the inner part 100 comprises a structure 104, which was preferably provided by injection molding.

[0135] In this embodiment, the structuring 104 of the end wall 103 comprises a plurality of rings 105a - 105n extending concentrically around the nozzle 101 of the inner part 100, which are formed as mountains or elevations.

[0136] These rings 105a - 105n are interrupted by a multitude of radially extending grooves 106, which, in conjunction with the outer part 200, form an anti-rotation device.

[0137] Fig. 8 is a top view of the distal side of the syringe body 2.

[0138] The end wall of the tip body 2 comprises a two-layered area 7 in which the structurings 104, 208 of inner part 100 and outer part 200 interlock.

[0139] The interlocking structure formed according to the invention is thus, as shown in particular in the detailed illustration according to Fig. 9 along section line B according to Fig. 5 shown, formed by the structuring 104 of the inner part 100 and by the structuring 208 of the end wall 211 of the outer part 200 which engages in this structuring 104.

[0140] The structuring 104 of the inner part 100 comprises a plurality of teeth 105a - 105n in a radial sectional view. In this embodiment, the structuring 104 is thus designed as a sawtooth profile in an axial section.

[0141] The correspondingly shaped teeth of the second material of the outer part 200 engage between the teeth 105a - 105n.

[0142] The second material extends around the outer walls of the entire interior part 100.

[0143] In this embodiment, the structuring (104 / 208) is designed as a regular structuring in which the distance between mountain and mountain or valley and valley (or elevation and elevation or depression and depression), i.e., the structure width, is defined by the distance a between two peaks or two valleys.

[0144] Furthermore, the structuring 104 / 208 has a maximum depth t, which defines the structural depth and is defined by the vertical distance between the peak of the mountain and the base of the valley.

[0145] The threaded connection 201 with the teeth 203 of the internal thread, which is opposite the nozzle 210, transitions via a bead 205 in the area of ​​the second material into the end wall 202 of the outer part 200.

[0146] This increases the mechanical strength in this area, thus reducing the risk of the threaded connection 201 breaking off.

[0147] Within the threaded connection 201, the base 207 of the threaded connection 201 extends to an inner corner 212, at which the end wall 211 of the outer part 200 transitions into the nozzle 210.

[0148] The nozzle 4 is therefore designed in two layers, namely from the nozzle 101 of the inner part 100, which provides the inner wall of the nozzle 4 and from the nozzle 210 of the outer part 200, which provides the outer wall of the nozzle 4.

[0149] Fig. 7 is a sectional view along line C of the Fig. 5 .

[0150] The cut now runs through a radial groove 106 of the inner part 100. The groove 106 is formed by interrupting the teeth or rings 105a-105m of the structuring 104 in a radially extending strip.

[0151] A corresponding bridge 209 made of the second material is formed in the groove 106.

[0152] This, in conjunction with the groove 106, forms an anti-rotation device.

[0153] In this embodiment, a ring 105n extending directly to the threaded connection 201 is not recessed by the groove 106.

[0154] This also forms a deflection point in the area of ​​bridge 209, through which the input of stresses into the area of ​​bridge 209 is reduced.

[0155] Inner part 100 and outer part 200 can be joined by material bonding, in particular by overmolding the inner part 100 with the outer part 200. Alternatively, it is possible to join the inner part 100 and outer part 200 by welding or bonding, or by a form-fit and / or force-fit connection.

[0156] The invention could provide a syringe 1 that is more stable, in particular less prone to brittle fracture, and has an improved feel. At the same time, the required amount of cycloolefin could be reduced. Reference symbol list

[0157] 1 Syringe 2 Syringe body 3 Internal volume 4 Nozzle 5 Threaded connection 6 Piston 7 Handle 8 Piston rod 9 Seal 10 Two-layer area with structuring 100 Inner part 101 Nozzle 102 Side wall 103 End wall 104 Structuring of the inner part 105a-105n Ring / Tooth 106 Radial groove 107 Collar 200 Outer part 201 Threaded connection 202 Side wall 203 Tooth 204 Handle 205 Bead 206 Top 207 Base 208 Structuring of the outer part 209 Web 210 Nozzle 211 End wall 212 Corner

Claims

1. A syringe body (2) for a medical syringe (1), comprising a nozzle (4) and a threaded connection (5), wherein the syringe body (2) is formed from an inner part (100) and an outer part (200), wherein the inner part (100) forms an inner wall of the syringe body (2) and comprises a cycloolefin as the first material, wherein the threaded connection (5) is formed as part of the outer part (200) from a plastic which comprises a material other than the cycloolefin as the second material, wherein the nozzle (4) is formed in two layers, from the nozzle (101) of the inner part (100), which provides the inner wall of the nozzle (4), and from the nozzle (210) of the outer part (200) which provides the outer wall of the nozzle (4) and the side wall of the syringe body (2) is formed in two layers and is formed from a side wall (102) of the inner part (100) and an adjoining side wall (202) of the outer part (200), wherein the outer part (200) extends at least in sections around the side wall (102) of the inner part (100).

2. The syringe body (2) according to the preceding claim, characterised in that the outer part (200) extends around the entire side wall (102) of the inner part (100) and / or in that a handle of the syringe body (2) is part of the outer part (200).

3. The syringe body (2) according to one of the preceding claims, characterised in that the inner part (100) and the outer part (200) are inserted into one another and, in particular, are connected at least in sections in a materially-bonded manner.

4. The syringe body (2) according to one of the preceding claims, characterised in that the inner part (100) is overmoulded with the outer part (200).

5. The syringe body (2) according to one of the preceding claims, characterised in that the wall thickness of the inner part (100), in particular in the region of the side wall and / or the end wall, is 0.3 to 3 times, preferably 0.5 to 1.5 times, the wall thickness of the adjoining wall of the outer part (200).

6. The syringe body (2) according to one of the preceding claims, characterised in that a front side of an end wall (103) of the inner part (100) comprises a structuring (104) into which a complementary structuring (208) of the outer part engages.

7. The syringe body (2) according to one of the preceding claims, characterised in that the structuring (104 / 208) of the inner part (100) and / or of the outer part (200) is each in the form of a profile with a plurality of elevations and / or depressions.

8. The syringe body (2) according to one of the preceding claims, characterised in that the structuring has at least one radially extending groove or a radially extending web, preferably a plurality of radially extending webs (209) and / or grooves (106).

9. The syringe body (2) according to one of the preceding claims, characterised in that a layer of the second material around the threaded connection (5) is thickened relative to a radially adjoining region of the layer of the second material.

10. The syringe body (2) according to one of the preceding claims, characterised in that the second material has a higher notched impact strength than the first material, in particular at least 20%, preferably at least 50%, higher notched impact strength than the first material.

11. The syringe body (2) according to one of the preceding claims, characterised in that the second material is softer than the first material.

12. The syringe body (2) according to one of the preceding claims, characterised in that the structuring on the front side of the end wall (103) of the inner part (100) is delimited by a radially circumferential web.

13. A syringe (1) comprising a syringe body (2) according to one of the preceding claims.

14. The syringe (1) according to one of the preceding claims, characterised in that the nozzle (5) is closed with a seal (9), preferably engaging in the nozzle (5), and in that the syringe comprises a piston (6) with a piston rod (8) for dispensing a medical liquid through the nozzle (4).

15. The syringe (1) according to one of the preceding claims, characterised in that the syringe is arranged in an oxygen-impermeable outer package.